Tehran , Iran -LRB- CNN -RRB- -- Nearly 90 professors at Iran 's oldest and largest university signed a letter to Supreme Leader Ayatollah Ali Khamenei , criticizing the government 's violent handling of student protesters .

`` The issue that has left a bitter taste in the mouths of the devout Muslim and patriots of this land is the violent and above the law -LSB- illegal -RSB- encounters , particularly with University students and faculty members of this land , '' says the letter , which was posted on the reformist Web site `` Rahesabz , '' or `` Green Path . ''

`` In fact , the nightly attacks on the dormitories and living quarters of innocent students and daily assaults on them ... are not testaments to the power of the system , just as the violent beatings and imprisonments are not testament to its faith and piety . ''

The professors ask Khamenei to order revolutionary guards , government-sanctioned militiamen and others who have engaged in campus violence to vacate the university . The letter also calls for official apologies for beatings of university members and the unconditional release of detained students and faculty .

There was no immediate government response to the letter .

The 88 professors -- all of whom are considered employees of the Islamic republic -- who signed the letter are `` risking their jobs and God knows what else , '' said Ali Alfoneh , a research fellow at the Washington-based American Enterprise Institute who has researched the relationship between Iranian civilians and the Islamic Revolutionary Guard .

`` Some of them may end up arrested , '' he added .

The letter , posted on a reformist Web site Monday , is a rare and significant showing of discontent among Tehran University 's academics . Student unrest has only increased since thousands of protesters turned out on the streets of Iran to oppose the country 's disputed presidential election , in which hardline incumbent President Mahmoud Ahmadinejad was declared the overwhelming winner .

`` Unfortunately and sadly ; all of this takes place under the veil of safeguarding Islam and the representation of the supreme leadership and , even more sadly , no institution or organization accepts responsibility for this savagery ! ''

The anti-government demonstrations began following the disputed June 12 presidential vote , which re-elected hardline President Mahmoud Ahmadinejad over main opposition candidate Mir Hossein Moussavi . Last month marked the deadliest clashes since the initial protests broke out this summer . At least seven people were killed and hundreds arrested as they took to the streets on Ashura , a Shiite Muslim holy day .

One university researcher told CNN he was one of many beaten by police , struck with a baton 11 times . Iranian Interior Minister Mostafa-Mohammad Najjar warned Saturday that the government will not show leniency to protesters in the future .

`` It does n't surprise me that professors wrote this letter , because universities have been one of the first victims of increased government pressure , '' Alfoneh said .

In the aftermath of the election , Tehran University and other institutions quickly became hotbeds of violence , with members of the government 's Basij militia attacking young protesters on campus , including dormitories .

In August , Khamenei addressed a group of university professors from all over , noting that academics would be held to a higher standard of accountability -- especially after the elections .

`` Naturally , the expectations that we have of the professors and faculty is much greater than what we expect from the students , '' Khamenei was quoted by Iranian media as saying on August 30 . `` The students are the young officers on the front lines of this war and the professors are the commanders -LSB- against -RSB- this ` soft war ' -- the professors who can fulfill this role will be worthy of the Islamic republic . ''

The Iranian government has denied that its security forces killed anyone and has blamed reformists for the violence . At times , video has shown protesters apparently turning on security forces .

Still , the letter serves as another blow to Iran 's Islamic leadership , which reformists say has lost credibility in its handling of the post-election unrest . Several critics , including cleric and former presidential candidate Mehdi Karrubi have compared the tactics of the current government to those of the Shah of Iran , who was overthrown by the same fervent followers of Islam more than 30 years ago .

Alfoneh noted that numerous petitions were drafted and published in the days leading up to the overthrow of the Shah , who was also slammed with allegations of injustice and human rights violations under his watch . He said it 's no surprise that academics today are taking a similar approach as it becomes increasingly harder to teach amid the violence .

`` The opposition and even ordinary citizen are trying to duplicate the events of 30 years ago -- they 're trying to play to the memory of the public , '' Alfoneh said .

CNN 's Samira Simone contributed to this report .

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Nearly 90 Tehran professors sign letter to Supreme Leader Ayatollah Ali Khamenei

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Letter criticizes government 's violent handling of student protesters

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Letter seeks apologies for beatings of university members and release of students , faculty

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Anti-government demonstrations began following the disputed June 12 presidential vote